Generally, various types of compressors can be adopted according to a compression method, and a scroll compressor is mostly used for an air-conditioner which requires a small and light one.
FIG. 1 is a sectional view of a scroll compressor in accordance with a conventional art.
The conventional scroll compressor includes: a casing 106 having a suction pipe 102 for sucking fluid and a discharge pipe 104 for discharging compressed fluid, and having a closed space therein; a driving unit 108 disposed at a lower portion of the casing 106 and generating a driving force; and a compressing unit 110 disposed at an upper portion of the casing 106 and being connected to the driving unit 108 by a rotational shaft 112 to compress fluid.
Inside the casing 106, a main frame 114 is installed to rotatably support the rotational shaft 112 and also supports the compression unit 110, and a separating panel 120 is installed to divide the interior of the casing 106 into a low pressure chamber (first chamber) 116 and a high pressure chamber (second chamber) 118.
The driving unit 108 consists of a stator 122 fixed in a circumferential direction of the casing 106 and a rotor 124 disposed at an inner circumferential surface of the stator 122 and fixed at the rotational shaft 112. When power is applied to the stator 122, the rotor 124 is rotated according to an interaction of the stator 122 and the rotor 124, to thereby rotate the rotational shaft 112.
The compression unit 110 consists of a fixed scroll 128 having a fixed vane 126 in an involute shape and being fixed at the separating plate 120, and an orbiting scroll 132 having an orbiting vane 130 in an involute shape corresponding to the fixed vane 126 to have a certain compression space between itself and the fixed vane 126, being supported in an orbiting manner at the support panel 114, and making an orbiting movement when the rotational shaft 112 is rotated.
A discharge passage 136 is formed at the center of the fixed scroll 128 in order to discharge fluid compressed according to an interaction of the fixed scroll 128 and the orbiting scroll 132 to the second chamber 118, and a check valve 138 is installed at an upper side of the discharge passage 136 to prevent a backflow of the fluid to the first chamber 116 after being discharged to the second chamber 118.
As shown in FIG. 2, the check valve 138 consists of a valve guide 150 bolt-coupled to the central upper surface where the discharge passage 136 of the fixed scroll 128 is formed, and having a guide hole 154 communicating with the discharge passage 136, and a valve member 152 disposed movable in a vertical directional at the guide hole 154 of the valve guide 150.
The guide hole 154 of the valve guide 150 is a certain space in which the valve member 152 is moved in a vertical direction within a certain range, and is connected to the second chamber 118 so that fluid introduced into the discharge passage 136 can be discharged to the second chamber 118.
The valve member 152 is a platy valve inserted to be movable in a vertical direction within a certain range, and performs an opening and closing operation on the discharge passage 136 by a pressure difference between the second chamber 118 and the first chamber 116.
In the check valve of the conventional scroll compressor, as the rotational shaft 112 is rotated according to driving of the driving unit 108, the orbiting scroll 132 is orbited. Then, the fluid sucked through the suction pipe 102 is compressed and then discharged to the discharge passage 136. At this time, the valve member 152 is moved in the upward direction along the guide hole 152 by the discharge pressure of the fluid, opening the discharge passage 136. Then, the fluid compressed in the compression unit 110 is supplied to the second chamber 118 through the guide hole 154 and then outwardly discharged through the discharge pipe 104.
When the compressor is stopped from operation, the valve member 152 is moved in a downward direction along the guide hole 154 due to the pressure difference between the high pressure chamber 118 and the low pressure chamber 116, and closely adhered to the upper side of the discharge passage 136, so that a backflow of the fluid in the high pressure chamber 118 to the low pressure chamber 116 is prevented.
However, the check valve of the conventional scroll compressor has the following problem.
That is, when the discharge passage is opened, the check valve is moved in the upward direction along the guide hole to collide with the guide hole, and when the discharge passage is closed to prevent a backflow, the check valve collides with the upper side of the discharge passage as being moved in the downward direction along the guide hole, creating a noise.
Especially, as the valve collides with at a certain region according to an amount of the compressed fluid and an operation condition of the compressor, a noise is generated therefrom to cause a users' inconvenience.